Strategies for lactase immobilization and delivery to relieve lactose intolerance

Approximately 70% of adults worldwide are affected by lactose malabsorption. Symptomatic lactose malabsorption is also known as lactose intolerance characterized by indigestion symptoms such as bloating, abdominal pain, and diarrhea. While many lactase-based approaches to relieve lactose intolerance are emerging, there has been a lack of timely and comprehensive evaluation of these approaches. Here, we summarize the application of lactase to relieve lactose intolerance. Specifically, we first introduce the classification of lactose intolerance and its harm, and then describe traditional methods to relieve lactose intolerance in which lactase is immobilized and used to eliminate lactose in food. Finally, we summarize the methods used to immobilize lactase. However, lactose-free diet can cause harm to human health, and lactase delivery as a dietary supplement can better address the nutritional and health needs of lactose-intolerant individuals. We then summarize the challenges associated with these new lactase preparations and the development of oral lactase delivery systems. Finally, we discuss the novel methods for lactase delivery, possibilities of improving its targeted delivery, and the remaining challenges. This review is expected to help rational design of effective oral lactase delivery platforms.